xref: /xnu-11215/tests/pread.c (revision e6231be0)
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28 
29 #include <darwintest.h>
30 #include <fcntl.h>
31 #include <unistd.h>
32 #include <sys/event.h>
33 #include <sys/mman.h>
34 #include <sys/socket.h>
35 
36 T_GLOBAL_META(
37 	T_META_NAMESPACE("xnu.syscall.pread"),
38 	T_META_RUN_CONCURRENTLY(true)
39 	);
40 
41 T_DECL(pread_regular_file,
42     "test pread() on a regular file.") {
43 	char scratchfile_path[] = "/tmp/scratch.XXXXXX";
44 	int fd = mkstemp(scratchfile_path);
45 	T_ASSERT_POSIX_SUCCESS(fd, "created temporary file");
46 	T_ASSERT_POSIX_SUCCESS(unlink(scratchfile_path), "unlinked temporary file");
47 
48 	char test_buffer[] = "a\0b";
49 	T_ASSERT_POSIX_SUCCESS(write(fd, test_buffer, 3), "wrote expected data");
50 
51 	char pread_output_buffer[4];
52 	bzero(pread_output_buffer, 4);
53 
54 	// Read one byte from zero.
55 	ssize_t result = pread(fd, pread_output_buffer, 1, 0);
56 	T_ASSERT_EQ(result, 1l, "pread 1 byte from 0");
57 	T_ASSERT_EQ(pread_output_buffer[0], 'a', "first byte output");
58 	T_ASSERT_EQ(pread_output_buffer[1], 0, "second byte output");
59 	T_ASSERT_EQ(pread_output_buffer[2], 0, "third byte output");
60 	T_ASSERT_EQ(pread_output_buffer[3], 0, "fourth byte output");
61 
62 	// Read all bytes from zero.
63 	bzero(pread_output_buffer, 4);
64 	result = pread(fd, pread_output_buffer, 3, 0);
65 	T_ASSERT_EQ(result, 3l, "pread 3 bytes from 0");
66 	T_ASSERT_EQ(pread_output_buffer[0], 'a', "first byte output");
67 	T_ASSERT_EQ(pread_output_buffer[1], 0, "second byte output");
68 	T_ASSERT_EQ(pread_output_buffer[2], 'b', "third byte output");
69 	T_ASSERT_EQ(pread_output_buffer[3], 0, "fourth byte output");
70 
71 	// Read more bytes than length from zero.
72 	bzero(pread_output_buffer, 4);
73 	result = pread(fd, pread_output_buffer, 4, 0);
74 	T_ASSERT_EQ(result, 3l, "pread 4 bytes from 0");
75 	T_ASSERT_EQ(pread_output_buffer[0], 'a', "first byte output");
76 	T_ASSERT_EQ(pread_output_buffer[1], 0, "second byte output");
77 	T_ASSERT_EQ(pread_output_buffer[2], 'b', "third byte output");
78 	T_ASSERT_EQ(pread_output_buffer[3], 0, "fourth byte output");
79 
80 	// Read one byte from 2.
81 	bzero(pread_output_buffer, 4);
82 	result = pread(fd, pread_output_buffer, 1, 2);
83 	T_ASSERT_EQ(result, 1l, "pread 1 byte from 2");
84 	T_ASSERT_EQ(pread_output_buffer[0], 'b', "first byte output");
85 	T_ASSERT_EQ(pread_output_buffer[1], 0, "second byte output");
86 	T_ASSERT_EQ(pread_output_buffer[2], 0, "third byte output");
87 	T_ASSERT_EQ(pread_output_buffer[3], 0, "fourth byte output");
88 
89 	// Read more bytes than length from 2.
90 	bzero(pread_output_buffer, 4);
91 	result = pread(fd, pread_output_buffer, 4, 2);
92 	T_ASSERT_EQ(result, 1l, "pread 4 bytes from 2");
93 	T_ASSERT_EQ(pread_output_buffer[0], 'b', "first byte output");
94 	T_ASSERT_EQ(pread_output_buffer[1], 0, "second byte output");
95 	T_ASSERT_EQ(pread_output_buffer[2], 0, "third byte output");
96 	T_ASSERT_EQ(pread_output_buffer[3], 0, "fourth byte output");
97 }
98 
99 static void
test_pread_should_fail(int fd,int expected_errno)100 test_pread_should_fail(int fd, int expected_errno)
101 {
102 	char output_buffer = 'A';
103 	ssize_t pread_result = pread(fd, &output_buffer, 1, 0);
104 	int err = errno;
105 	T_ASSERT_EQ(pread_result, (ssize_t)-1, "pread offset 0 size 1 returns -1");
106 	T_ASSERT_EQ(err, expected_errno, "errno is as expected");
107 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
108 
109 	pread_result = pread(fd, &output_buffer, 1, 1);
110 	err = errno;
111 	T_ASSERT_EQ(pread_result, (ssize_t)-1, "pread offset 1 size 1 returns -1");
112 	T_ASSERT_EQ(err, expected_errno, "errno is as expected");
113 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
114 
115 	pread_result = pread(fd, &output_buffer, 0, 0);
116 	err = errno;
117 	T_ASSERT_EQ(pread_result, (ssize_t)-1, "pread offset 0 size 0 returns -1");
118 	T_ASSERT_EQ(err, expected_errno, "errno is as expected");
119 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
120 
121 	pread_result = pread(fd, &output_buffer, 0, 1);
122 	err = errno;
123 	T_ASSERT_EQ(pread_result, (ssize_t)-1, "pread offset 1 size 0 returns -1");
124 	T_ASSERT_EQ(err, expected_errno, "errno is as expected");
125 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
126 }
127 
128 T_DECL(pread_socket,
129     "test pread() on a socket.") {
130 	int sockets[2];
131 	int result = socketpair(AF_UNIX, SOCK_STREAM, 0, sockets);
132 	T_ASSERT_POSIX_SUCCESS(result, "Created socket pair");
133 
134 	test_pread_should_fail(sockets[0], ESPIPE);
135 	test_pread_should_fail(sockets[1], ESPIPE);
136 
137 	T_ASSERT_POSIX_SUCCESS(close(sockets[0]), "Closed socket 0");
138 	T_ASSERT_POSIX_SUCCESS(close(sockets[1]), "Closed socket 1");
139 }
140 
141 T_DECL(pread_unix_shared_memory,
142     "test pread() on unix shared memory.") {
143 	const char* memory_path = "test_pread_unix_shared_memory";
144 	int shm_fd = shm_open(memory_path, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
145 	T_ASSERT_POSIX_SUCCESS(shm_fd, "Created shared memory");
146 
147 	test_pread_should_fail(shm_fd, ESPIPE);
148 
149 	T_ASSERT_POSIX_SUCCESS(close(shm_fd), "Closed shm fd");
150 	T_ASSERT_POSIX_SUCCESS(shm_unlink(memory_path), "Unlinked");
151 }
152 
153 T_DECL(pread_kqueue,
154     "test pread() on kqueue.") {
155 	int queue = kqueue();
156 	T_ASSERT_POSIX_SUCCESS(queue, "Got kqueue");
157 
158 	test_pread_should_fail(queue, ESPIPE);
159 
160 	T_ASSERT_POSIX_SUCCESS(close(queue), "Closed queue");
161 }
162 
163 T_DECL(pread_pipe,
164     "test pread() on pipe.") {
165 	int pipe_fds[2];
166 	T_ASSERT_POSIX_SUCCESS(pipe(pipe_fds), "Created pipe");
167 
168 	test_pread_should_fail(pipe_fds[0], ESPIPE);
169 	test_pread_should_fail(pipe_fds[1], EBADF);
170 
171 	T_ASSERT_POSIX_SUCCESS(close(pipe_fds[1]), "Close write pipe");
172 	T_ASSERT_POSIX_SUCCESS(close(pipe_fds[0]), "Close read pipe");
173 }
174 
175 T_DECL(pread_read_from_null,
176     "test pread() from null.") {
177 	int fd = open("/dev/null", O_RDONLY);
178 	T_ASSERT_POSIX_SUCCESS(fd, "Opened /dev/null");
179 
180 	char output_buffer = 'A';
181 	ssize_t pread_result = pread(fd, &output_buffer, 1, 0);
182 	T_ASSERT_EQ(pread_result, (ssize_t)0, "pread offset 0 size 1 returns 0");
183 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
184 
185 	pread_result = pread(fd, &output_buffer, 1, 1);
186 	T_ASSERT_EQ(pread_result, (ssize_t)0, "pread offset 1 size 1 returns 0");
187 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
188 
189 	pread_result = pread(fd, &output_buffer, 0, 0);
190 	T_ASSERT_EQ(pread_result, (ssize_t)0, "pread offset 0 size 0 returns 0");
191 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
192 
193 	pread_result = pread(fd, &output_buffer, 0, 1);
194 	T_ASSERT_EQ(pread_result, (ssize_t)0, "pread offset 1 size 0 returns 0");
195 	T_ASSERT_EQ(output_buffer, 'A', "input buffer is unchanged");
196 
197 	T_ASSERT_POSIX_SUCCESS(close(fd), "Closed /dev/null");
198 }
199